An offset printer includes a dampening apparatus used therein, and the dampening apparatus includes a water fountain roller on the water supply side and a water applying roller on a printing unit side and is configured to transfer dampening water from the water fountain roller to the water applying roller (Patent Literature 1).
There is also a known dampening apparatus for an offset printer including a divided roller unit for transferring water disposed between a water fountain roller on the water supply side and a water applying roller on the printing unit side, in which the divided roller unit for transferring water includes a plurality of water transfer rollers divided in an axial direction of both rollers described above, and the water transfer rollers are configured to be switched individually between a water transfer position where the water transfer roller comes into contact with the water fountain roller and the water applying roller and a non-water transfer position where the water transfer roller is out of contact with at least one of the water fountain roller and the water applying roller (Patent Literature 2).
There is also a known dampening apparatus for an offset printer including a plurality of air blowing portions disposed in a line along an axial direction of a water transfer roller and configured to blow air to the roller (Patent Literature 3).